Gemini ACP - Use of Tool Call Title for MCP tools

[jwflicker]

Looking at Gemini as an ACP reference, the title it returns for "sessionUpdate":"tool_call" for MCP tools does not seem to be the name or the title of the tool, but rather the input values passed into the tool. Does this seem like a bug?

For example, for a tool named/titled: "listProblems", Gemini ACP returns

{
   "jsonrpc":"2.0",
   "method":"session/update",
   "params":{
      "sessionId":"f1fb46f8-008f-4ba5-b695-15dbe17952e8",
      "update":{
         "sessionUpdate":"tool_call",
         "toolCallId":"listProblems-1765359923416",
         "status":"in_progress",
         "title":"{\"resourceURI\":\"file:/Users/jflicke/runtime-New_configurationAgents1234/XMLEditor\"}",
         "content":[
            
         ],
         "locations":[
            
         ],
         "kind":"other"
      }
   }
}

where it seems like the "TITLE" gets the input content sent into the tool call. The spec says:

title: A human-readable title describing what the tool is doing
for example:

"toolCallId": "call_001",
"title": "Reading configuration file",

Meanwhile, the MCP spec for listProblems is:

{ name: "listProblems"
  title: "List Problems",
  description: "list Eclipse IDE compilation and configuration problems",
  inputSchema: { ... },
  annotations:  {
    title: "List Problems",
    ...
  }
}

The json input should probably be moved to rawInput right?

I can open a gemini bug/feature for this, wanted to check here first though.

[benbrandt]

Hmm I would say this does seem strange, but would need to be changed on the Gemini CLI side you are correct

[jwflicker]

google-gemini/gemini-cli#14957